title: Mitral valve replacement in infants and children 5 years of age or younger: evolution in practice and outcome over three decades with a focus on supra-annular prosthesis implantation.
abstract: OBJECTIVE
  Successful mitral valve replacement in young children is limited by the lack of small prosthetic valves. Supra-annular prosthesis implantation can facilitate mitral valve replacement with a larger prosthesis in children with a small annulus, but little is known about its effect on the outcomes of mitral valve replacement in young children.
  
  
  METHODS
  One hundred eighteen children underwent mitral valve replacement at 5 years of age or younger from 1976-2006. Mitral valve replacement was supra-annular in 37 (32%) patients.
  
  
  RESULTS
  Survival was 74% +/- 4% at 1 year and 56% +/- 5% at 10 years but improved over time (10-year survival of 83% +/- 7% from 1994-2006). Factors associated with worse survival included earlier mitral valve replacement date, age less than 1 year, complete atrioventricular canal, and additional procedures at mitral valve replacement, but not supra-annular mitral valve replacement. As survival improved during our more recent experience, the risks of supra-annular mitral valve replacement became apparent; survival was worse among patients with a supra-annular prosthesis after 1991. A pacemaker was placed in 18 (15%) patients within 1 month of mitral valve replacement and was less likely in patients who had undergone supra-annular mitral valve replacement. Among early survivors, freedom from redo mitral valve replacement was 72% +/- 5% at 5 years and 45% +/- 7% at 10 years. Twenty-one patients with a supra-annular prosthesis underwent redo mitral valve replacement. The second prosthesis was annular in 15 of these patients and upsized in all but 1, but 5 required pacemaker placement for heart block.
  
  
  CONCLUSIONS
  Supra-annular mitral valve replacement was associated with worse survival than annular mitral valve replacement in our recent experience. Patients with supra-annular mitral valve replacement were less likely to have operative complete heart block but remained at risk when the prosthesis was subsequently replaced.
authors.affiliation: Department of Cardiology, Children's Hospital, Boston, Massachusetts 02115, USA.
authors.forename: Elif Seda
authors.initials: ES
authors.lastname: Selamet Tierney
authors.forename: Frank A
authors.initials: FA
authors.lastname: Pigula
authors.forename: Charles I
authors.initials: CI
authors.lastname: Berul
authors.forename: James E
authors.initials: JE
authors.lastname: Lock
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: del Nido
authors.forename: Doff B
authors.initials: DB
authors.lastname: McElhinney
mesh_terms: D000367:Age Factors; D002675:Child, Preschool; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008943:Mitral Valve / Q000002:abnormalities*; D008944:Mitral Valve Insufficiency / Q000151:congenital / Q000401:mortality / Q000601:surgery*; D008946:Mitral Valve Stenosis / Q000151:congenital / Q000401:mortality / Q000601:surgery*; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000401:mortality; D011336:Probability; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome